Parameters into Call Library Function Node not being passed

I am trying to configure an instrument using IVI Instrument drivers. In the first vi that does this, the instrument (a sig gen) is being set correctly to the desired frequency and power. In a second vi I try to change the frequency and power, the sig gen does not change.
If I run the second vi stand-alone with the original settings, again there is no change. But if I change the value of frequency or power by any amount, that parameter is now set properly on the sig gen.
When I look at the IVI vi, I can see that the parameters I send in are getting to the Call Library Function Node.
Any idea what the problem is.
Thanks.
p.s., Are there instructions on how to paste a picture or link to a vi into my post. This question would have been a lot easier and clearer to ask.

Hi cgantz,
While it sounds, possibly, like a "state-caching"-related bug in the IVI driver, it certainly would be good to have a look at your code. Look a the bottom-left area of the "Message Body" when replying - there's an "Attachment" tool for this purpose!
Cheers.
"Inside every large program is a small program struggling to get out." (attributed to Tony Hoare)

Similar Messages

Call Library Function Node not Supported

Hai,
I have question to ask to NI members. I get an error said " Call Library Function Node 'LVASPT_WA.*ptDecimationFilterH':Node not supported". I use the call library function node in the FPGA.VI in my design. My question is, is it the function cannot used in FPGA.VI? I try to search a similar thread and find the manual but still can't find the answer. Anyone please clarify it to me. Thanks in advance.

You cannot use Call Library Function Node in FPGA. The FPGA is hardware - it has no way to call an external library. If it is not immediately obvious why it's impossible for the FPGA to call a DLL, you should spend some time understanding what a FPGA is.
You can integrate FPGA code written outside the LabVIEW environment, but that's not the same as calling a DLL.

Call Library Function Node: library not found or failed to load

Hello,
I had a VI that could not find some of the dll functions it needed. It works on one machine and not on another. So foolishly I copied the dll in question from the working machine and pasted it over the one on the non-working machine.
Now all my math functions are broken on the machine I copied the dll too. The error is "Call Library Function Node: library not found or failed to load"
And if I try to relink in the VI I get "Error loading C:\National Instruments\LabVIEW 8.2\resource\lvanlys.dll" A dynamic link library (DLL) initialization routine failed."
I tried a repair labview and that did not help.
I tried uninstall and reinstall labview and that did not help!
Please help me fix this!
Version 8.2
dll: C:\National Instruments\LabVIEW 8.2\resource\lvanlys.dll
Jim

What library did you first copy?
Also lvanlys.dll depends on the Intel Math Kernel Library that gets installed in a different location "C:\Program Files\National Instruments\Shared\MKL".
This Intel Math Kernel Library again depends on the Visual C runtime libraries. Most likely you replaced one of those runtime libraries somehow and now the Math Kernel Library (MKL) fails to initialize which causes thelvanlys.dll to fail its load.
Without a good view on your system and what other NI software you have installed it is very hard to recommend a good way of proceeding. There are various versions of the MKL used by various versions of NI products and just deleting the entire MKL folder might get you into trouble with other NI tools.
Deinstalling everything from NI, deleting the entire National Instruments folder and then reinstalling what you need would be the most safe proceeding.
And next time don't just copy some Visual C runtime libraries between machines. Their dependencies are complicated at the least and simply not graspable by us mere mortals. Use the according C runtime installer for the version you need as that installer will take care of installing the right versions of C runtime components and registering everything proberly so you do not usually run into problems with other applications using different versions of the C runtime.
Message Edited by rolfk on 03-01-2010 10:26 AM
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

DIO Port Config & DIO Port Write Block Diagram Errors (Call Library Function Node:library not found or failed to load)

Hi Guys, need help on this.
I have this LabVIEW program that used to work on the old computer.
The old computer crashes most of the time, so I upgraded the computer
and used its Hard Drive as slave to the new computer.
I have no idea where are its installers since the guy that made the program
is not in my department anymore.
I downloaded all the drivers needed from NI: NIDAQ9.0, NIVISA,NI488.2,
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Everything's fine until I open the LabVIEW program for our testing.
Here goes the error:
   DIO Port Config
   DIO Port Write
Block Diagram Errors
   Call Library Function Node: library not found or failed to load
Attachments:
ErrorList.JPG ‏200 KB

Honestly, I'm a newbie on Labview. I just want this old program to run on the new computer.
The guys that installed the drivers on the old computer are no longer here in my department.
And I have no idea where the drivers are. So I just downloaded the drivers needed for my hardware and instruments.
Here's my hardware: (cards: PCI-DIO-96, PCI-GPIB), (instruments: SCB100,E4407B, HP83623, HP3458, HP8657)
OS: Windows XP Pro
By the way, I have unzipped the TraditionalDAQ drivers. First I tried the 7.4.1, but installation error appeared.
I thought maybe the installer is corrupted, so I downloaded the 7.4.4 and unzipped it.
But, still same installation error appears. I don't understand, both TraditionalDAQ drivers have same installation error.
Now I have tried the DAQmx8.7.2 driver, bu still the DIO Port Config and DIO Port Write have errors.

Call Library Function Node 'Wrapper.Create': Library not found or failed to load. using windows 7 64 bits

Dear all
I try to interface my spectrometer (NIRquest from ocean optics) using labview on my 64 bits cumputer using windows 7.
I have absolutely no problem to run the spectrometer with the program dedicated to the spectrometer (called Spetrasuite).
I've installed "OmniDriverSPAM-1.66-win64-development-installer.exe" and everything went right.
When I select a VI in LabView (e.g."wrapper_create.vi") from the wrapper.llb, LabView returns an error :
"Call Library Function Node 'Wrapper.Create': Library not found or failed to load."
I chek the call library function, but everyting seems to be right :
I use LabView 8.6.1 and my others *.vi are running perfectly...
Do you have any idea from where does the problem comes ?
Thank you very much

Hello Flanguy,
In addition to smercurio_fc's feedback I can confirm that LabVIEW 8.6.1 doesn't exist in 64-bit version.
Officially, LabVIEW 8.6.1 doesn't support Windows 7 either.
The minimal version of LabVIEW you would need to both support Windows 7 and exist in 64-bit version is LabVIEW 2009 64-bit or any 64-bit versions which are more recent.
In the two links (1 & 2) you can find more background information.
Kind Regards,
Wouter
National Instruments Belgium

Call library function node - function not found

When creating a DLL I get a the Labview error "Call Library Function Node "LabviewReceiverDLL.dll:readDataJ1939Data' Function not found. Everything looks correct to me and this used to work, though I've changed computers since then.
This is the beginning of my C++ code just to show my function name. I've also attached the Call Library Function Window to show my setup.
Thank you in advance for your help.
#include"StdAfx.h"
#include<iostream>
/* Call Library source file */
extern"C"__declspec(dllexport)unsignedint readDataJ1939Data(unsignedint, unsignedint, unsignedchar, unsignedchar* canData, unsignedchar* path);
unsigned int readDataJ1939Data(unsignedint ulTimeStamp, unsignedint ulIdentifier, unsignedchar uiDataCount, unsigned char* canData, constchar* path)
Solved!
Go to Solution.
Attachments:
Call Library Function.png ‏192 KB

You mention that you have changed computers and that it used to work before.
Could it be that there is another (older) copy of the DLL on this computer, and LabVIEW is loading the wrong one?
The simplest way to check is to close your VI and delete the one you are expecting it to use. Then open the VI again; if LabVIEW doesn't ask you where the DLL is, it is loading it from somewhere else.
Batya

Call library function node: function not found in library

I'm using Labview 6.1 and Windows XP. I am trying to open some code, but it opens up with a broken arrow. The error is Call Library Function Node:function not found in library. Tried to configure the node, but no change. Moved the DLLs to various directories (keeping them together) but again no change.
This code has been compiled and is working fine. I'm just trying to run the source code to make some modifications. Any suggestions?
Thanks
CarlosV

Thanks for the suggestions. Tried it but had the same results. The library I'm using is hpe1413_32.dll.
One thing I forgot to mention....doing a configure on the node, it comes up with the library: hpvscp32.dll and the function: hpe1413_error_message
The function doesn't exist in the library. So I set the path to hpe1413_32.dll which does contain the function.
After closing the configuration window and opening it up again, the library shown is hpvscp32.dll
From what I can tell, there are three libraries involved:hpe1413_32.dll, hpe141332v.dll, and hpvscp32.dll
Thanks again.
Carlos

Using variants in Call Library Function Node parameters

Can I use Call Library Function Node to send variant data?
Attached is a VI. Here's the C code:
int MM_FUNC mmDaqDll_407DB
    ( IN char *pcUdlPath
    , IN char *pcTableName
    , IN void *pvData
    int nStat = 1;
    //System:bject *varData = ((System:bject *)vData);
    MessageBox(NULL, pcUdlPath, pcTableName, 0);
    return nStat;
} // mmDaqDll_407DB()
I get the void pointer. I was hoping for a solution that did not use void*.
What is the best way to pass void data to a DLL?
Attachments:
DaqDllMon407DB.vi ‏18 KB

Hi Mefitzpatrick,
Here is a similar forum that addresses this issue:
http://forums.ni.com/ni/board/message?board.id=170&message.id=48886&requireLogin=False
They mention using the Adapt to Type property of the function node inputs, have you tried this?
Let me know if this doesn't answer your question.
Sappster

Call library function node with array of clusters using array data pointer

Hello all.
I am writing a LabVIEW wrapper for an existing DLL function.
The function has, as one of its parameters, an array of structs. The struct is very simple, containing two integers. I am using the call library function node to access it.
In Labview I created an array of clusters, where the cluster has two 32-bit integers as its members. So far, so good.
Now I have to pass this in to the Call Library Function Node. Here I am running into trouble.
I have used The topic in LAVA and The topic in the knowledge base as my primary sources of information, though I have read a bunch of forum topics on the subject too.
I do understand that I could write a new function which takes as a parameter a struct with the size as the first member and an array as the second, and I might just do this and have it call the regular function, but I was hoping to do it more simply.
According to the C file which LabVIEW generates for me from the CLFN when I choose "Adapt to Type" and "Array Data Pointer", the prototype it is expecting is:
int32_t myFunc(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, void data[], int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex);
And the prototype of the function in my DLL is
int borland_dll myFunc(DWORD handle, usint channel,
int FIFOnumber, struct mStruct *data, int numWords, int *actualLoaded, int *actualStartIndex);
This looks like a match to me, but it doesn't work (I get garbage in data). From the topic in LAVA referenced above, I understood that it would work. It does not.
If I cast data to the pointer-to-pointer I get when I generate c code by wiring my struct to a CIN and generating, then I seem to get what I expect. But this seems to work when I choose "pointers to handles" too, and I would expect array data pointer to give a different result.
Is there any way to get this to work directly, or will I have to create a wrapper? (I am currently using LabVIEW 2011, but we have customers using 2009 and 2012, if not other versions as well).
Thank you.
Batya
Solved!
Go to Solution.

OK, here is more detailed information.
I have attached the VI.
This is the code from the "C" file created by right-clicking the CLN and creating a "C" file.
When the parameter in the CLN is set to "array data pointer":
/* Call Library source file */
#include "extcode.h"
int32_t Load_Transmit_FIFO_RTx(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, void data[], int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex);
int32_t Load_Transmit_FIFO_RTx(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, void data[], int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex)
/* Insert code here */
When the parameter is "pointers to handles":
/* Call Library source file */
#include "extcode.h"
/* lv_prolog.h and lv_epilog.h set up the correct alignment for LabVIEW data. */
#include "lv_prolog.h"
/* Typedefs */
typedef struct {
int32_t control;
int32_t data;
} TD2;
typedef struct {
int32_t dimSize;
TD2 data[1];
} TD1;
typedef TD1 **TD1Hdl;
#include "lv_epilog.h"
int32_t Load_Transmit_FIFO_RTx(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, TD1Hdl *data, int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex);
int32_t Load_Transmit_FIFO_RTx(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, TD1Hdl *data, int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex)
/* Insert code here */
When the parameter is set to "handles by value":
/* Call Library source file */
#include "extcode.h"
/* lv_prolog.h and lv_epilog.h set up the correct alignment for LabVIEW data. */
#include "lv_prolog.h"
/* Typedefs */
typedef struct {
int32_t control;
int32_t data;
} TD2;
typedef struct {
int32_t dimSize;
TD2 data[1];
} TD1;
typedef TD1 **TD1Hdl;
#include "lv_epilog.h"
int32_t Load_Transmit_FIFO_RTx(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, TD1Hdl *data, int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex);
int32_t Load_Transmit_FIFO_RTx(uint32_t handle, uint16_t channel,
int32_t FIFOnumber, TD1Hdl *data, int32_t numWords, int32_t *actualLoaded,
int32_t *actualStartIndex)
/* Insert code here */
As to the DLL function, it is a bit more complicated than I explained above, in the current case. My VI calls the function by this name in one DLL, and that DLL loads a DLL and calls a function (with the same name) in the second DLL, which does the work. (Thanks Rolfk, for helping me with that one some time back!)
Here is the code in the first ("dispatcher") DLL:
int borland_dll Load_Transmit_FIFO_RTx(DWORD handle, usint channel, int FIFOnumber, struct FIFO_DATA_CONTROL *data, int numWords, int *actualLoaded, int *actualStartIndex)
t_DispatchTable *pDispatchTable = (t_DispatchTable *) handle;
int retStat = 0;
retStat = mCheckDispatchTable(pDispatchTable);
if (retStat < 0)
return retStat;
if (pDispatchTable->pLoad_Transmit_FIFO_RTx == NULL)
return edispatchercantfindfunction;
return pDispatchTable->pLoad_Transmit_FIFO_RTx(pDispatchTable->handlertx, channel, FIFOnumber, data, numWords, actualLoaded, actualStartIndex);
borland_dll is just "__declspec(dllexport)"
The current code in the DLL that does the work is:
// TEMP
typedef struct {
int control;
int data;
} TD2;
typedef struct {
int dimSize;
TD2 data[1];
} TD1;
typedef TD1 **TD1Hdl;
// END TEMP
int borland_dll Load_Transmit_FIFO_RTx(int handlertx, usint channel, int FIFOnumber, struct FIFO_DATA_CONTROL *data, int numWords, int *actualLoaded, int *actualStartIndex){
struct TRANSMIT_FIFO *ptxFIFO; //pointer to transmit FIFO structure
usint *pFIFOlist; //pointer to array of FIFO pointers to FIFO structures
int FIFOentry, numLoaded;
usint *lclData;
usint nextEntryToTransmit;
// TEMP
FILE *pFile;
int i;
TD1** ppTD = (TD1**) data;
TD1 *pTD = *ppTD;
pFile = fopen("LoadFIFOLog.txt", "w");
fprintf(pFile, "Starting Load FIFO with %d data words, data pointer 0x%x, with the following data&colon; \n", numWords, data);
for (i = 0; i < numWords; i++) {
fprintf(pFile, "%d: control--0x%x, data--0x%x \n", i, data[i].control, data[i].data);
fflush(pFile);
fprintf(pFile, "OK, using CIN generated structures: dimSize %d, with the following data&colon; \n", pTD->dimSize);
for (i = 0; i < numWords; i++) {
fprintf(pFile, "%d: control--0x%x, data--0x%x \n", i, pTD->data[i].control, pTD->data[i].data);
fflush(pFile);
// END TEMP
if ((handlertx) <0 || (handlertx >= NUMCARDS)) return ebadhandle;
if (cardrtx[handlertx].allocated != 1) return ebadhandle;
pFIFOlist = (usint *) (cardrtx[handlertx].segaddr + cardrtx[handlertx].glob->dpchn[channel].tr_stk_ptr);
pFIFOlist += FIFOnumber;
ptxFIFO = (struct TRANSMIT_FIFO *)(cardrtx[handlertx].segaddr + *pFIFOlist);
//use local copy of ptxFIFO->nextEntryToTransmit to simplify algorithm
nextEntryToTransmit = ptxFIFO->nextEntryToTransmit;
//on entering this routine nextEntryToLoad is set to the entry following the last entry loaded
//this is what we need to load now unless it's at the end of the FIFO in which case we need to wrap around
if ( ptxFIFO->nextEntryToLoad >= ptxFIFO->numEntries)
*actualStartIndex = 0;
else
*actualStartIndex = ptxFIFO->nextEntryToLoad;
//if nextEntryToLoad points to the last entry in the FIFO and nextEntryToTransmit points to the first, the FIFO is full
//also if nextEntryToLoad == nextEntryToTransmit the FIFO is full and we exit without loading anything
if (( (( ptxFIFO->nextEntryToLoad >= ptxFIFO->numEntries) && (nextEntryToTransmit == 0)) ||
( ptxFIFO->nextEntryToLoad == nextEntryToTransmit)) && (ptxFIFO->nextEntryToLoad != INITIAL_ENTRY)){
*actualLoaded = 0; //FIFO is full already, we can't add anything
return 0; //this is not a failure, we just have nothing to do, this is indicated in actualLoaded
numLoaded = 0;
lclData = (usint *)data; //must use 16 bit writes to the module
//conditions are dealt with inside the for loop rather than in the for statement itself
for (FIFOentry = *actualStartIndex; ; FIFOentry++) {
//if we reached the end of the FIFO
//if the module is about to transmit the first element of the FIFO, the FIFO is full and we're done
//OR if the module is about to transmit the element we're about to fill in, we're done - the
//exception is if this is the first element we're filling in which means the FIFO is empty
if ((( FIFOentry >= ptxFIFO->numEntries) && (nextEntryToTransmit == 0)) ||
((FIFOentry == nextEntryToTransmit) && (FIFOentry != *actualStartIndex) )){
*actualLoaded = numLoaded;
//set nextEntryToLoad to the end of the FIFO, we'll set it to the beginning next time
//this allows us to distinguish between full and empty: nextEntryToLoad == nextEntryToTransmit means empty
ptxFIFO->nextEntryToLoad = FIFOentry;
return 0;
//we reached the end but can continue loading from the top of the FIFO
if ( FIFOentry >= ptxFIFO->numEntries)
FIFOentry = 0;
//load the control word
ptxFIFO->FifoData[FIFOentry * 3] = *lclData++;
//skip the high of the control word, the module only has a 16 bit field for control
lclData++;
//now put in the data
ptxFIFO->FifoData[(FIFOentry * 3) + 2] = *lclData++;
ptxFIFO->FifoData[(FIFOentry * 3) + 1] = *lclData++;
numLoaded++;
//we're done because we loaded everything the user asked for
if (numLoaded >= numWords) {
*actualLoaded = numLoaded;
ptxFIFO->nextEntryToLoad = FIFOentry+1;
return 0;
//if we reached here, we're done because the FIFO is full
*actualLoaded = numLoaded;
ptxFIFO->nextEntryToLoad = FIFOentry;
fclose (pFile);
return 0;
As you can see, I added a temporary diagnostic with the structures that were created in the "Handles by value" case, and print out the data. I see what is expected, whichever of the options I pick in the CLN!
I understood (from the information in the two links I mentioned in my original post, and from the name of the option itself) that "array data pointer" should pass the array of data itself, without the dimSize field. But that does not seem to be what is happening.
Batya
Attachments:
ExcM4k Load Transmit FIFO.vi ‏15 KB

Description to pass 'enum' to a call library function node

Hi,
I'm looking for some description/help regarding how to pass 'enum' to a call library function node.
The API documentation that I have states something like this:
enum ibApi_DEVICETYPE_e {
ibApi_DEVICETYPE_A = (1<<0),
ibApi_DEVICETYPE_B = (1<<1),
ibApi_DEVICETYPE_C = (1<<2),
ibApi_DEVICETYPE_D = (1<<3),
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typedef ibApi_UINT32 ibApi_DEVICETYPE;
The above is one of the input parameters to my call library function node. Hint to some documentation/example VI should be enough.

An enum requires sequential values, so you wouldn't be able to enter an arbitrary value for each of the enumeration items. You can still use an enum, but you would need a small "accessor" VI that converts the enum to a number. I do this often, as I prefer enums. You can, however, use a ring constant which allows you to enter your own values for each of the labels. With a ring constant you can enter the value based on a format you've selected. By default the format is "Automatic", which means you enter a decimal value. If you right-click on the ring constant and select "Format & Precision" you can change it "Hexadecimal". Then, in the "Edit Items" tab you can enter a hex value in the "Values" column. So, you would have a row that has "ANY" in the "Items" column and "3F" in the "Values" column. This is only if you prefer to see the values in hex.
Tip: You should make this into a typedef.
Note: The values for each of the constants are not 0, 1, 3, but rather 1, 2, 4, 8, etc...

Failed to run parallel path when using call library function node in LV2009

I have a problem with two parallel paths not being run in parallel on LabView 2009.
See the image below.
This code initializes an external device, the upper part contains a call library function node to download my code into the device. When done, the function returns and the "Done" flag is set to True.
The lower part contains a call library function node to check the download status, reporting the percentage of downloaded code.
This updates a progress bar that is referenced by the calling VI module and this works fine in LV 7, 8 and 2011. The lower path of the VI updates the progress bar while the CLFN in the upper part is still downloading code to my device.
Somehow, in LV2009 this does not work when running this inside my application. When running just the calling VI (the window showing the progress bar) it works but not when that VI is called by my application.
Is there some limit on parallel threads that is different in 2009 than in other versions ?
Or is there some other problem in 2009 that might cause this problem ?
My labview version is 9.0f3 (32-bit).
Regards,
Rob

I've just installed the DETT tool and checked what the different versions of LabView do.
In LV2009 the application instance runs in a thread (5) but the modal dialog (the VI above) then drops to thread 0 and stays in thread 0.
In LV2011, stays in the same thread as the application instance and only a trigger event (this could be the progress bar reference?) is executed in thread 0.
So it seems there is a 'feature' in LV2009 where modal dialogs are by default not following the preferred execution system set in the VI properties ...
When I change this from "same as caller" into another thread (I used "other 1") then my progress bar works as expected.
I'm not a LabView thread expert (not even a novice ) so I'm just guessing that "other 1" as a thread is OK. This VI only runs during startup of the application to download the code to my device.
To answer Ben's question: "What thread does a modal VI run in?":
In LV2009, the modal VI runs in thread 0 (UI thread ?). When the preferred execution system is set to another thread, the modal dialog still starts in thread 0 but then switches over to the other thread.
In LV2011, the model VI runs in the caller's thread (preferred execution system set to "follow caller") from start.
Thanks,
Rob

How to call a C pointer from call library function node

I have a client/server application which the client I am trying to develop using Labview. When I use to communicate the server and the client using the program provided by the manufacter, the system works perfectly.
Now, I am trying to develop a system using labview, because I need to get another things.
I have the DLL provided by the manufacter and the .h too, so I can check the functions parameters. One of these functions needs to be called using a struct element. Probably, the function's DLL instantiates the elements of this struct. I use the call library function node to do it.
When I receive the data, the function returns to me the struct that I passed as a parameter before, and then I can read all the elements of the struct, except the string element that returns nothing. The struct elements that are numerical, I can read them perfectly.
Another thing that is important to say, is that the string data was not returned in fact by the DLL function that the system calls. I have to pass a pointer (I use it as unsigned 16 in Labview, but I tried before as string and unsigned 8) as a parameter, and this pointer will point to the memory location that the string is. When I try to read what is returned by the function, I can read nothing. The same function returns that the size of data that is returning is 17 bytes.
How can I solve it?
Thank you in advance

Did you take a look at the example that ships with LabVIEW that shows how to do all sorts of data passing to DLLs. I believe your situation is one of the examples listed. You can find the example VI in the "<LabVIEW install directory>\examples\dll\data passing" directory.

How to implement a callback function using LabView's Call Library Function Node?

I am trying to call a fuction from a SDK.dll library using the Call Library Function Node. The SDK was provided to
me and I do not have the source code, just the .dll and .h files.
The SdkSetPropertyEventHandler function has a callback fuction as one of its parameters. How do I implement the
callback using the CLF node? I am a good LabView programmer but this is my first time using the Call Library
Function Node. I have read all the info I can find on NI's web site and the discussion board but cannot figure
this one out. I am using LabView 8.6.
The SDK.h deacribes the function as:
// Function:   SdkSetPropertyEventHandler
SdkError SDKAPI SdkSetPropertyEventHandler(
            SdkCameraRef                    inCameraRef,
            SdkPropertyEvent                inEvnet,
            SdkPropertyEventHandler         inPropertyEventHandler,
            SdkVoid*                        inContext );
// Description:
//       Registers a callback function for receiving status
//          change notification events for property states on a camera.
// Parameters:
//       In:    inCameraRef - Designate the camera object.
//              inEvent - Designate one or all events to be supplemented.
//              inPropertyEventHandler - Designate the pointer to the callback
//                      function for receiving property-related camera events.
//              inContext - Designate application information to be passed by
//                      means of the callback function. Any data needed for
//                      your application can be passed.
//      Out:    None
// Returns:    Any of the sdk errors.
A separate header file called SDKTypes.h contains the following data:
typedef SdkUInt32 SdkPropertyEvent;
typedef SdkUInt32 SdkPropertyID;
typedef void       SdkVoid;
typedef struct __SdkObject*    SdkBaseRef;
typedef SdkBaseRef    SdkCameraRef;
SdkPropertyEventHandler
typedef SdkError ( SDKCALLBACK *SdkPropertyEventHandler )(
                    SdkPropertyEvent        inEvent,
                    SdkPropertyID           inPropertyID,
                    SdkUInt32               inParam,
                    SdkVoid *               inContext );
Thanks for your help.
Alejandro
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alejandroandreatta wrote:
I am trying to call a fuction from a SDK.dll library using the Call Library Function Node. The SDK was provided to
me and I do not have the source code, just the .dll and .h files.
The SdkSetPropertyEventHandler function has a callback fuction as one of its parameters. How do I implement the
callback using the CLF node? I am a good LabView programmer but this is my first time using the Call Library
Function Node. I have read all the info I can find on NI's web site and the discussion board but cannot figure
this one out. I am using LabView 8.6.
Basically you do not do that. LabVIEW does not know pointers and certainly not function pointers. What you should do instead is writing a C DLL that implements the callback and also exports a function to be called by LabVIEW that translates between the callback and a LabVIEW user event. Look for PostLVUserEvent() here on the NI site to find examples how to do that.
Rolf Kalbermatter
Message Edited by rolfk on 02-11-2009 08:00 PM
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Execution time for Call Library Function Node

I am experimenting with the Call Library Function Node block in LabVIEW and am curious if it should be running faster than what I'm seeing. For testing purposes, I have compiled and transfered to my RT target the .out file from the KB article http://digital.ni.com/public.nsf/allkb/81D1172E3C28A5E4862575CC0076A230 (I'm using the vxworks 6.1 version). The function in the .out file just multiplies two inputs together, adds a constant, and returns the result. I have put this inside a 1 kHz timed loop with a commanded period of 1 ms and via the Ticks(ms) block and shift registers I calculate the amount of time per loop execution. This process is apparently taking 5 ms per cycle and to me that seems slow. Is that roughly the correct execution time for this kind of setup? I will attach my test .vi file.
What I'm using:
Windows 7
LabVIEW 2009 SP1
NI-cRIO 9024 with NI-RIO 3.4.0
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Attachments:
test DLL.vi ‏31 KB

First off, the way you are doing timing isn't necessarily accurate because you don't know when the tick count VI is being called. For example, if it gets called on one iteration after your call library node executes, and the next iteration it gets called before the CLFN it executes, the subtraction doesn't include the call of the CLFN so you aren't seeing the true time it is taking for the dll to be called.
Where it says "error" on the top left hand corner of your loop. left click and choose previous iteration timing. Also, do you have the ability to choose a 1 Mhz clock? Are you sure it's actually being run on the RT and not on your PC? Running it on the PC would definitely make it difficult to execute at a 1 kHz rate.
CLA, LabVIEW Versions 2010-2013

Call Library Function Node.vi using problem

Hi,
我用Labwindows 编了个读文件的程序然后生成动态库, 然后在LabVIEW里调用该动态库(Call Library Function Node), 即向该动态库传递文件名及路径和某一字符串,然后该动态库打开相应路径文件从中读出并返回三个参数值,可是每次的返回值总显示打开文件失败, 该函数在Labwindow里没有问题. 在LabVIEW里如何调试来确定传到动态库的参数格式是没有问题的呢?任何的指点迷津,不胜感激!
Frank,

xiejiezhou wrote:
Thank Georges and Rolf Kalbermatter,
I changed the runtime support with " Full Runtime Engine" instead of " LabVIEW Real-Time Only" before, it's work now, but the output parameters returned are irregular incorrect characters. My funciton prototype is:
DLLEXPORT long CollectParameter(char *NomFile, char *szNomParagraph, char *Command[], char *Type[], char *Value[])
so how to configure the type in LabVIEW respectively? I tried every types, just "c String Pointer" is ok, but returned value irregular & incorrect.
As Geogre's suggestion, i should add my code as below function generated by LabVIEW, is it?
ong CollectLabel(char szNomFile[], char szNomParagraph[], char Command[], char Type[], char Value[])
/* Insert code here */
Frank
The char *Command[], char *Type[], char *Value[] parameters are parameters that you can not create with LabVIEW. This are arrays of strings and and LabVIEW has a completely different idea about how to place strings and arrays in memory than what is used in C.
And while LabVIEW supports translation of the top level type to C compatible pointers it does not have any option to let you configure it to translate embedded elements in parameters (the strings in the array) to be translated too.
But to be honest what you seem want to do is read in a file, do some parsing and then return parameters taken out of that file. Doing that all in LabVIEW would be SOOOOOOOOOOOO much easier.
Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Parameters into Call Library Function Node not being passed

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